Assessment of Genetic Divergence through Principal Component Analysis and Clustering in Tomato Germplasm Accessions

Abstract

The base material of this study comprises of 104 tomato accessions including local landraces, varieties and germplasm collections. The collected tomato accessions were evaluated using 13 quantitative traits by Principal Component Analysis (PCA) and Hierarchial clustering. PCA was done to quantify diversity among the germplasm accessions and also the contribution of individual traits towards diversity. In our study, only the first four (PC1, PC2, PC3 and PC4) of the thirteen principal components yielded eigen value more than one indicating the greater influence of identified traits under study. The first six PCs accounts for 84% of variability whereas, PC1 exhibited 41% of total variability. Cluster analysis aids to classify the genotypes based on the grouping pattern of the accessions under evaluation. According to the dendrogram obtained, cluster analysis grouped 104 tomato accessions into two significant clusters. The first cluster consists of 16 genotypes whereas, the second cluster consists of 88 genotypes. Among the genotypes used in this study EC617055, EC617061, EC638302, Periakulam local and EC631390 were found to be best performing in terms of yield and quality. These accessions can be used as a base material in future breeding programs.